This research pertains to the detection and definition of chromosome changes in neoplasias, concentrating on selected patients with lymphomas, ataxia-telangiectasia, teratomas and possibly related tumors. An element in the experimental design is its longitudinal aspect: patients and cell lines in which repeat chromosome studies are feasible will be followed, the aim being to observe clonal evolution. Methods will include direct chromosome studies, modifications in short-and long-term cell culture, use of appropriate differential chromosome banding techniques, sequential staining and visual analysis of banding patterns; other methods will include cell culture scanning photometry of banded chromosomes and semi-automated densitometry. Our immediate aims are to collect evidence for the possible clonality of these lymphoid neoplasmas, and of teratomas and other gonadal tumors, to improve methodology for studying chromosomes from neoplastic cells, to establish these cells in long-term culture and to delineate patterns of chromosome change in individual types of neoplasms, correlating cytogenetic data with the patient's course. Our long-term aims are (1) to learn general principles applicable to chromosome rearrangements in neoplastic cells; (2) to determine if interlocking patterns of chromosome change exist, embracing two or more clinically distinct disorders; and thereby (3) to collect evidence as to what factors such as cell type may influence the patterns of chromosome aberration in neoplastic cells; and (4) to learn more about cell biology and genetics from studying neoplastic cells.